WEB.API does not deserialize incoming JSON in POST method

Question

I have created Web.Api based on .Net-Core. There are two methods:

IEnumerable GetRoles() - (Get)
ResponseObject GetUsers(PagerRequest pagerRequest) - (Post). It has the following attributes: [Route("api/users/getusers")] [HttpPost]

Both methods are called by Angular. Method GetRoles is working find but problem is in POST.

PagerRequest is a simple class which has a few int properties. It's filled in by Angular. Fiddler shows correct JSON:

POST http://localhost/Pir.API/api/users/getusers HTTP/1.1
Host: localhost
Connection: keep-alive
Content-Length: 84
Accept: application/json, text/plain, */*
Origin: http://localhost:4200
User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36
content-type: application/json
Referer: http://localhost:4200/
Accept-Encoding: gzip, deflate, br
Accept-Language: ru-RU,ru;q=0.9,en-US;q=0.8,en;q=0.7

{
  "CountButtons": 5,
  "ItemsCount": 0,
  "PageSize": 5,
  "CurrentPageIndex": 0
}

GetUsers method is calling but input parameter is not initialized. In another words desirialization is not working and I cannot understand why.

Before this project was based on classic .Net and run in the IIS. It was working fine. But .Net CORE is a problems.

Who knows where the problem is?

Below code examples:

-------------- PagerRequest.cs --------------------

public class PagerRequest
{
     public int ItemsCount { get; set; }
     public int PageSize { get; set; }
     public int CurrentPageIndex { get; set; }
     public int CountButtons { get; set; }
 }

-------------- PagerRequest.ts --------------------

export class PagerRequest{
    ItemsCount:number;
    PageSize:number;
    CurrentPageIndex:number;
    CountButtons:number;    
}

score 6 · Accepted Answer · answered Sep 25 '18 at 07:36

6

You need to tell the framework to read the data from the request body. Do this with the FromBody Attribute

[HttpPost]
ResponseObject GetUsers([FromBody]PagerRequest pagerRequest)

Note: If performing a HttpPost, the name GetUsers is missleading. A tip is to change that

answered Sep 25 '18 at 07:36

Marcus Höglund

16,172
11
47
69

Thanks. It helped. Why was it working in classing application without this attribute? – Mike Tkachev Sep 25 '18 at 07:49
1

@MikeTkachev Np, please accept answer :), In Asp.Net Web Api/MVC reading request data from the body was default in Controller methods. – Marcus Höglund Sep 25 '18 at 08:47

score 0 · Answer 2 · answered Sep 25 '18 at 07:46

1) You are missing the FromBody.

2) One tip while working on apis is to configure Swagger . Swagger creates a sample html by default where you can see what type of request body is needed from the UI frameworks (for example see this url https://petstore.swagger.io, all the api endpoints are visible as html by default and we can see the type of request needed).

Hope this helps.

WEB.API does not deserialize incoming JSON in POST method

2 Answers2